Telephone-exchange apparatus.



F. W. ADSIT.

TELEPHONE EXCHANGE 'A'PPARATUS.

APPLICATION FILED MARJL 191s.

Patented Feb. 29, 1917.

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FRANK W. ADS'IT, OF v1V ['I1\T1\TIEAPOLIS, MINNESOTA, ASSIGNOR TO ADSIT GENERAL ELEC- TRIO COMPANY, OF MINNEAPOLIS, MINNESOTA, A CORPORATION OF MINNESOTA.

TELEPHONE-EXCHANGE APPARATUS.

Specification of Letters Patent.

Patented Feb. 20, 1917.

Application fiIeclMarch 17, 1915. Serial No. 15,114.

To all whom it may concern: v

Be it known that I, FRANK V7. Ansrr, a citizen of the United States, residing at Minneapolis, in the county of Hennepin and State of Minnesota, have invented new and useful Telephone-Exchange Apparatus, of which the following is a specification.

My invention relates to improvements in telephone exchange apparatus, of which the following is a full description, reference being had to the accompanying drawings forming a part of this specification.

My invention relatesmore particularly to means for controlling the duration of a telephone conversation and provides means whereby the conversation may be automatr cally interrupted and the circuits restored to the normal condition without supervision of the operator. i

This invention is particularly well adapt ed to be used in connection with conversation originating from toll stations, and particularly such toll stations as are equipped with the ordinary class of coin boxes.

In the ordinary operation of such stations, it is the practice for a call to be put through in the following manner.'

The party making the call at the coin loo); will first call the central operator in the ordinary manner and give the number of the party he wishes to talk with.

The operator uses her answering plugin answering the call, and with her calling plug makes a connection with the jack corresponding to the party wanted, and makes the call in the ordinary manner.

When the called party answers, the operator who is still supervising the line, tells the calling party to drop in the proper coin. When this is done, the operator is notified by suitable means, and allows the conversation to proceed.

', The conversation may extend over an indefinite period and is ended only when the parties thereto hang, their receivers on the hooks thus signaling the central operator whodisconnects in theordinary manner.

It is the growing practice of operating telephone companies to make their charges for telephone service in proportion to the amount the subscriber uses the telephone.

It has become apparent to theoperating companies that the commodity they are selling to the public is time, and the true measure of service is the length of time the telephone apparatus is in use.

Attempts have-been made to devise an equitable means of charging for service by the method of handling it is cumbersome and expensive as it requires a great deal of supervision by the operator.

By means of my invention, the operating companies can'sell their service on the basis of the time used, which is equitable, and furthermore the operation automatically gives the subscriber the exact length of conversation paid for, and at the same time minimizes the amount of supervision required by the. operator.

In the accompanying drawing, is shown a common form of line circuit in which 5 represents the j ack, 22 the cut 015? relay, 50 the linerelay and 51 the line lamp.

The jack 2 would be wired to similar lamp and relays which for simplicity are omitted,

the art. 56 and 57 are subscribers sets of ordinary type.

The cord circuit shown in the drawing is of a common type ordinarily associated with the line circuit shown, except that my invention is added into the calling side of the cord circuit.

The answering side of the cord circuit operates in a manner known to the telephone art and for simplicity, a description is omitted.

A party making a call will signalthe central operator in the usual manner (not shown) and the operator will insert her answering plug 1 intothe jack 2'corresponding to the calling party, then by throwing the listening key 3 she connects in her set (not shown) in the ordinary inanner and ascertains the number wanted.

She then inserts the calling plug 4: into the jack 5 corresponding to the desired party and rings the party by throwing the ringing key 6, which connects the ringing current in the ordinary manner (not shown).

W hen the calling plug 1 is inserted into the jack 5, a circuit is established as follows: 7

From battery 7 through wires 8, 5), 10, supervisory lamp 11, wires 12, 13, and 1%, contact 16, wire 17, operating coil 18, wire 19, the sleeve of the calling plu 20, sleeve of the jack 21, winding of cut-oil relay to the other side of the battery 7, which is grounded at 23. This lights the supervisory lamp 11 operates the cut-cit relay 22 which clears the line signaling apparatus from that line in the usual manner and energizes the coil 18 whose armature 2-1 is prevented from operating by the latch 25' \Vhen the called party answers, the battery 7 is fed out through the windin A-A of therepeating coil, through the supervisory relay 26, through the key, plug, jack, line and subscribers instrument in the ordinary manner.

The relay 26 being thus energized, a circuit is completed as follows:

From battery 7, wire 8, wire 52, relay contact 27, wire 28, key contact 29, operating coil 30, wire 31, wire 1-1, contact 16, wire 17, coil 18, wire 19, sleeve of plug 20, jack sleeve 21, coil 22, to the other side of battery which is grounded at Y This energizes the coil 30 which pulls the gear 31 into mesh with the constantly driven pinion 32. The gear 31 being carried on the supporting arm 36L, which is pivoted at 33, will be normally held out of mesh with the pinion 32 by the spring 35. The coil 30 also serves to shunt the supervisory lamp 11 so it will be dark.

The pinion 32 which is constantly driven by any suitable method (not shown) now drives the gear 31 in an antic-lock-wise direction, and this motion is continued for a certain pre-determined time, which for the purpose of description, we will call five minutes.

Just before the expiration of the five minutes, possibly fifteen seconds, the arm 36 carried by the gear 31, lifts the spring 37, causing it to make contact at 38, which brings a tone signal from a tone test circuit 55, on to the established line circuit as follows:

Source of tone signal, wire 39, spring 37, contact 38, wire -10 to one side of the line back through the subscribers loop to wire 11, contact 1-2, wire 43, to source of signal.

This tone signal in the subscribers instrument, which of course is heard in both instruments, is to advise them the period of conversation for which the calling party has paid, is practically finished. They may then either terminate their conversation or the calling party can signal the operator and by paying a second time, obtain a sec ond five minute talking period.

Should the parties continue talkin the arm 36 in its continued motion will strike the lower end of the latch lever 25, releasing armature 24, which will be drawn up, thus opening the talking circuit between the two subscribers. This also opens the circuit of the supervisor relay 26, hence its armature is released and the contact at 27 is opened, thus opening the circuit of operating coil 30, and the gear 31 is swung back to normal position by thespring and the arm 36 is restored to normal position by the spring 53.

The supervisory lamp 11, which has been shunted out during conversation by the coil 30, will now be illuminated, informing the operator the circuit has been disconnected, and she can dis-connect her cords in the ordinary manner, unless the calling party sig nals her he wishes another five minute period. Should he do so, the operator can, by momentarily opening the key contact 16, re lease the armature 24; of the coil 18, putting it again under the control of the latch 25, which again completes the circuit, drawing the gear 31 into mesh with the constantly driven pinion 32 and starting a second five minute period, which will be identical with the first.

Should the operator wish for any reason, such as in the case of a long distance call,

to hold up the operation of the timing mechanism, she can do so by throwing the key 44: to connect in the resistance coil 15 in place of the operating coil 30.

The supervision on the hanging up of either subscriber is standard and the timer is released by the opening of the contact 27 in the same manner when the receiver is hung upon the hook as when the contact 24 is broken through the operation of coil 18 already described.

The act of withdrawing the plug 4 from the jacko restores the timer, as it opens all the circuits thus releasing all of the mechanism. The restoring of the latch 25 to its normal position is clearly shown by the drawing through the action of the arm 36,

which when returning to normal, presses upon the lever 46 which is pivoted to the member 47, moving this member about its pivot 48 through pressure on the pin 4-9, and the other end of the lever 17 thrusts the stem 54 to the left, thus restoring the latch V 25 and the armature 2 1 to their normal positions. V

l/Vhile in this specification and drawing, my invention is shown in connection with acertain cord circuit and associated with a certain class of subscribers line, it is evident theinvention may be applied directly to various types of circuits used in the telephone and signaling field and I do not wish to be understood as confining myself to the application or arrangement of parts as described.

Having described my invention, what I claim as new and desire to protect by Letters Patent is:

1. Telephone exchange apparatus comprising a line circuit, a subseribers set, a cord circuit in the central station, adapted to cooperate with said line circuit, and means associated with said cord circuit, adapted to open the connection between said cord circuit and said line circuit at the end of a predetermined period.

2. In a telephone system, the combination of a cord circuit having an answering side and a calling side, a line circuit, timing mechanism having rotatable means controlled by the calling side of said cord circuit and'means in the timing means forshutting ofl said timing means at the end of a predetermined period.

3. In a telephone system, the combination of a cord circuit havin an answering side and a calling side, a line circuit, timing mechanism having rotatable means controlled by the calling side of said cord circuit and means in the timing means for shutting off said timing means at the end of a predetermined period and a tone circuit including a contact closable by said timing means just prior to the shutting off of said timin -means.

4. n a telephone system, the combination of a line circuit, a cord circuit having an answering side and a calling side, timing mechanism, electromagnetic starting means for said timing mechanism controllable by the electrical condition of the calling side of said cord circuit, a contact cl osable by said timing mechanism at the end of a predetermined period, a Contact in the talking circuit of said cord circuit, electromagnetic means for opening said contact and mechanical means for preventing the operation of said electromagnetic means prior to the expiration of a certain predetermined period.

FRANK W. ADSIT.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

7 Washington, D. G. 

